Building structure



FIG. 1 is a perspective view of my design for a building structure;

FIG. 2 is a front side elevational view of the design of FIG. 1;

FIG. 3 is one end elevational view of the design of FIGS. 1 and 2, the opposite end being a mirror image thereof;

FIG. 4 is a rear side elevational view of my design for a building structure as shown in FIGS. 1 through 3 above. 

The ornamental design for a building structure, as shown and described. 